Core drill



Ef s. HARTsoN CORE DRILL Filed' May 25, 1928 W@ 715" a/l/ gde June 1,6, 1931,'

Patented June 16, 1931 PATENT OFFICE EARL S. HARTSON, OF LOS ANGELES, CALIFORNIA CORE DRILL Application filed May 25, 1928. Serial No. 280,515.

My invention relates generally to well drilling apparatus, and more particularly to a core drill, that is a drill for obtaining a core of subterranean formation, such, for instance,

as are necessary and desirable in the drilling of oil wells, and the principal objects of my invention are to generally improve upon and simplify the construct-ion of the existing forms of core drills and to provide a drill that is driven downwardly through the formation by the impact of hammer-like blows.

A further object of my invention is to provide a relatively simple, practical and inexpensive core drill that may obtaining oriented cores, and which latter,

in addition to showing the structure and nature of the formation through which the drill is driven, maintains the core and delivers the same to the operators of the drill in the same relative position that said core occupie when cut from the formation at the bottom of the well hole.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that Will 'hereinafter be more fully described and claimed and illustrated in the accompanying drawings, in which- Fig. 1 is a vertical section taken lengthwise through the center of a core drill of my improved construction.

Fig. 2 is an enlarged vertical section taken through the intermediate portion of the body of the drill and showing the means utilized '35 for tripping the hammer to produce a downward blow upon the drill. 4

Fig.` 3 is a horizontal section taken on the line 3-3 of Fig. 2. 40 Referring by numerals to the accompanying drawings which illustrate a practical em-l bodiment of my invention, 10 designates a tube of metal that forms the core barrel, the lower end of which carries a drill 11, which latter may be of any desired type, and carried by the upper end of the core barrel is a downwardly seating check valve 12 which permits air to discharge from thev upper end of the barrel as the latter 1s driven downwardly around a core, and said check valve preventbe employed for I,

d mediate member 13 is a plug 18 through which ing the downward passage of fluid or mud into the core barrel. 4

The core barrel 10 is axially disposed within an elongated tubular housing that comprises an intermediate member 13, an upper member 14 and a lower member 15, said members being connected by screw joints and the upper end of the upper member being eXternally threaded in order to be readily connected to the lower end of a drill pipe.

The lower portion of the lower member 15 is provided with a bearing 16 through which the lower portion of the core barrel is adapted to slide freely, and screw seated in the upper end of said lower member 15 is a plug 17 of hardened metal which functions as an anvil and through which the core barrel is arranged to slide freely.

Screw seated in the upper portion of interthe core barrel is arranged to slide freely, and arranged to slide freely upon the core barrel within the chamber in the intermediate member 13 of the housing is a cylindrical block 19 that functions as a hammer, and the lower end of which hammer is adapted to engage on top of the anvil block 17 while the device is in operation. i

Interposed between the block 1 8 and the top of the hammer 19 and arranged lon the core barrel 10 is a relatively sti, expansive coil spring 20, the expansive force of which is utilized for driving the hammer 19 downwardly on to the anvil block 17.

Secured in any suitable manner on the core barrel 10 and arranged withinfthe chamber in the lower housing member 15 is a collar 21 and interposed between the said collar and the lower end of the anvil 17 is an expansive coil spring 22 of considerably less tension than the spring 20.v

The function of this relatively light spring 22 is to exert downward pressure upon the core barrel and yieldingly retain thesame at the lower end of its movement relative to the housing 13.

Anvil block 17 is provided in its underside adjacent to the opening through which the core barrel passes with an annular recess 17 a, which is of sufficient length to receive the 100 tion of coils of spring 22 when the same is fully compressed, and when said spring is fully compressed the collar 21 that is rigidly fixed to the core barrel bears against the underside of anvil block 17. f

A portion of the body of hammer 19 just above its lower end is reduced in diameter as designated by 28, and formed through this reduced portion is a diametrically arranged opening 24 through which is arranged to slide freely a core barrel locking block or plate 25. One end of this block or locking plate is arranged to slide through a longitudinally disposed groove or channel 26-that is formed in the inner face of the wall of the intermediate member 13 of the housing and said block or plate is provided with an opening `27, the width of which is slightly greater than the diameter of the core barrel and the length thereof being such as to permit said block or plate to move lengthwise for a short distance upon said core barrel.

Secured to the outer face of the hammer 19 at the upper end of the reduced portion 23 thereof is one end of a flatfspring 28, the free end of which bears against theend of block or plate 25 opposite the end that occupies the groove or channel 26.

Formed in the periphery of the core barrel l0 is a circumferentially disposed groove 29 and when this groove is in alinement with the opening 24 spring 28 forces the block or plate 25 laterally a short distance or until a porsaid block or plate at the rear end ofthe opening 27 enters the groove 29 and thus the hammer 19 is locked to the core barrel.` Whenhammer 19 is at the lower end of its movement `with its lower end resting on top of the anvil 17, the groove 29- in the core barrel is in register with the opening 24 plate 25 engaging in the and the block or, groove 29 locks the hammer to the core barrel.

In the use of my improved core barrel the housing within which the barrel is arranged is secured to the lower end of a drill pipe and the device is lowered into the well until the drill 11 engages the formation at the bottom thereof. The drill pipe to which the housing is connected is now lowered with sufficient pressure to compress spring 20, and as the drill pipe is thus lowered the housing will move downwardly relative to the stationary drill core, the lower end of which is resting on the formation at the bottom of the well.

As the drill pipe is thus lowered and the core barrel remains stationary, spring 22 will compressed within the chamber 17a in anvil block 17 and simultaneously with the engagement of the collar 21 with the underside of the anvil block 17 the forward end of block or plate 25 will engage against the shoulder at the upper end of groove 26. As

va result of this engagement said block or plate w1ll move rearwardly a short distance through the opening 24,`thereby`disengaging the hammer 19 from the core barrel and said hammer under eXpanslve force of spring 20 will be driven downward until its lower end strikes on top of the anvil block 17 and transmits through collar 21 to the core barrel a downward blow or thrust thereon and consequently driving the drill 11 downwardly through the'formation at the bottom of the I which enables the well drillers or persons 0perating the core barrel to obtain positive and definite information as to the orientation of the subterranean structure from which the core is taken.

After the hammer 19 has been forced downwardly into engagement with the anvil block as just described, the drill pipe carrying the core barrel housing is elevated to 'permit spring 20 to expand and the expansive power of spring 22 retains the core barrel in position with its lower end against the formation at the bottom of the well and when the groove 29 in the core barrel registers with the Qpening 24 through the lower portion of the hammer, spring 28 will act to move plate or block 25 a short distance forwardly. Such action causes that portion of the block immediately to the rear of the opening 27 to enter groove 29, thereby vlocking the hammer to the core barrel andthe parts are now in position to repeat the core barrel driving operation as just described.

Thus it will be seen that I have provided a core drill that is relatively simple in construction, inexpensive of manufacture, and very effective in performing the function for which it is intended.

An especially desirable feature of my improved core drill is the arrangement and construction whereby oriented cores are produced and obtained, for such cores enable the well drillers to very accurately determlne the arrangement and position of the subterranean structure through which the core drill It will be understood that minor changes in the size, form and construction of the various parts of my improved core drill may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

v'1. In a core drill, a tubular body adapted to be connected to a drill pipe, a core barrel axially arranged in said tubular body, a drill carried by the lower end of said core barrel.

- latching the hammer core.

a spring pressed hammer arranged for sliding movement on said core barrel within said tubular body, an anvil block arranged in the lower portion of the tubular body, a shoulder on the core barrel which is adapted to engage against the said anvil block, and means for latching the hammer to said core barrel.

Y 2. In a core drill, a tubular body adapted to be connected to a drill pipe, a core barrel axially arranged in said tubular body, a drill carried by the lower end of said/ core barrel, a spring pressed hammer arranged for slid-V ing movement o'n said core barrel within said tubular body, an/anvil block arranged inthe lower portion of the tubular body, a shoulder on the core barrel which is adapted to engage. against the said anvil block, and means for to said core barrel, which latching means ls automatically re-f leased at the termination of a downward movement of predetermined length of the tubular member relative to said core barrel.

3. Ina core drill, a tubular body,"a core barrel axially disposed within said tubular body and arranged to move lengthwise theref in, a drill carried by the lower end of said core barrel, a check valve carried b theupper portion of said core barrel, yiel ing pressure means. for normally maintaining sai core barrel at the lower end -of its travel within said tubular body, and means includ; ing a spring actuated hammer for imparting downward driving blows to said drill 4. In a core drill, a tubularrbody, a core barrel' extending axially through said tubular body vand arranged to move lengthwise therein, an anvil 'blocl in the lower portion ofthe tubular body, a spring pressed hammer arranged for sliding movement within the tubular body above said anvil block a shoulder on the lower portion of the 'core barrel for engagement with the underside of' the anvil block, an expansive spring interposed between said shoulder and said anvil block, and means for latching said hammer to said core barrel.

5. In a core drill, a tubular body, a core v barrel extending axially through said` tubular body and arranged to move lengthwise..l therein, an anvil block in the lower portion of the tubular body, a spring pressed hammer arranged for sliding movement within the tubular body above said'anvil block, a shoulder on the lower portion of the core barrell for engagement with the underside l'of the anvil block, an expansive spring interposed between said shoulderand said anvil block, means for latching said hammer to said corebarrel, and means ly releasing said latching means atgthe termination of a downward movement of predetermined length of said tubular body relative to the core barrel..

or automatical 6. In a core drill, -a tubular body, a Vcore barrel axially arranged within said tubular body, 'an anvil block arranged in the lower portion of the tubular body, a'. shoulder on the core barrel, which shoulder is adapted to engage the underside of said anvil block, a spring pressed hammer arrangedfor sliding movement withinthe tubular body above the anvil block, a latching plate extending diametrically through the hammer an adapted to engage in a groove in the core barrel to lock the same spring bearing againstv the rear end of sald latching plate and the inner surface of said tubular body being provided with a longitudinally disposed groove that is traversed by the forward end'ot said latching plate during the relative vertical movements of said hammer and tubular body.

7. In a core drill, a core barrel, a drill carried by the lower end of said core barrel, a check valve carried by the upper portion ot' said core barrel, a tubular body within which said core barrel is arranged for lon-- gitudinal movement, a compression spring for resisting the upward movement of the core barrel within said tubular member, and means including a spring pressed hammer arranged for operation within said tubular body for imparting ,downward driving blows to said core barrel.

8. In a core drill,

Afor operation within said tubular body for imparting impact to said anvil and core 9. In a coredrill, a core barrel, a drill carried by the lower end of saidcore barrel', a tubular body within which the core barrel is arranged for longitudinal movementyan anvil fixedly arranged within the lower portion of the tubular body, a compression spring arranged between said. anvil and corel barrel for normally retaining the core barrel at the to said hammer, a

p a core barrel, a drill carlried by the lower end of said core barrel, a

lower end of its travel within said tubular body, a spring pressed hammer arranged for operationfwithin said Itubular body for imparting impact to said anvil and core barrel and means for latching said spring pressed EARL S. HARTSON.

vhammer to the core barrel during vupward I 

